For many years homes and businesses have utilized communication systems that enable fire and security system information to be transferred between remote sites (homes, businesses, etc.) and a security host monitoring station. Security companies such as Diebold, Wells Fargo, Brinks and ADT maintain large numbers of centralized monitoring stations that continually monitor security systems for subscribing customers. Each company uses a particular set of digitized codes or protocols, often simple number sequences, to determine the particular status of a security system. These protocols are typically proprietary to the particular security company.
FIG. 1 illustrates a security system monitoring arrangement according to the prior art. This patent will refer generally to protocols used by the ADT Company. However, the techniques described herein are applicable to a variety of companies employing various protocols, both for security systems and for other types of data transmission. As shown, customers at remote locations have respective alarm panels 100 and 102. Each alarm panel 100 and 102 is connected to a respective bank of sensors 110 and 112. In practice, each sensor bank 110, 112 can comprise a large number of sensors, each having specialized functions, such as motion detectors, open-door switches, smoke detectors and the like. The sensors 110 and 112 communicate locally with the respective alarm panel 100 and 102, providing security information to each panel.
The alarm panels each include conventional circuitry that translate sensor information into digital status signals. A modem 120 and 122 is provided in each respective panel. This modem, or an equivalent telephone communication device, interconnects the panel with the Public Switched Telephone System (PSTN) 130. A dedicated telephone line can be used to provide a continuous connection for the panel. Alternatively, each modem can include appropriate answering functions and dialing functions to allow periodic calls to be placed by the panel over the PSTN and for receiving calls over the PSTN when the panel senses a ring signal.
The security company, at its monitoring site, maintains a hosts computer or other monitoring devices 140. The host computer is interconnected with the PSTN and 130 by its own internal telecommunications modem 142 or other device. Like the panel, it is configured to place and receive calls over the PSTN, or to operate on a dedicated line to communicate with each panel.
The communication by the host with each panel is further described with reference to FIG. 2. The monitoring station, via the host computer 140 continually checks the status of each alarm panel on its given list of subscribers generally in a round robin fashion. Typically, a post poll select function (200) is executed by the host computer for a selected panel. As such, a call or polling function reads the selected alarm panel (202) via the PSTN. In response to the poll select, the panel transmits a status signal (204). In general, the status signal includes various station/alarm panel address information as well as specific security system status data. For example, according to the ADT protocol, the digital number "03" indicates an "all clear" status. Other numbers may indicate a system malfunction or security breach. The protocol used to poll the panel, and to return status does not include an "address" or other identifier indicating the identity of the particular polling host. This is because direct calls over the PSTN are made to and from the alarm panel (e.g. the host's location is always known). The polling procedure shown in FIG. 1 occurs in round robin sequence throughout a group of alarm panels until all panels have been polled, and responses have been received therefrom. This is an asynchronous process in which a poll occurs at the host, and a status response is sent by the alarm panel at a short, but indefinite, time thereafter. Once all alarm panels on the host's subscriber list have been polled, and status received, the polling process repeats itself.
As noted, the information transferred from each alarm panel does not include particular addresses about its destination (e.g. returning to the host). This limits the ability of such information to be transferred over a distributed network such as the well-known Internet where source and destination address information is needed to appropriate route data. For information to be effectively routed over the Internet, an Internet Protocol (IP) source and destination address is generally needed within the transmitted data stream or "packet."
Accordingly, the object of this invention that provide a method and apparatus for enabling information that does not include source and destination addresses to be returned to a host from a remote source following a asynchronous polling of the source by the host for that information. This method and apparatus should enable the existing hosts and alarm panels (or other data devices) configured to operate free of IP layer addressing functions to be used without significant modification.